KR20080028305A - Photomask blank and manufacturing method thereof, photomask and manufacturing method thereof, photomask intermediate, and pattern transcription method - Google Patents

Abstract

A photomask blank and a manufacturing method thereof, a photomask and a manufacturing method thereof, a photomask intermediate, and a pattern transcription method are provided to improve productivity by reducing the number of cleaning processes. A photomask blank includes a light transmitting substrate(1), a light shielding layer(2) formed on a main surface(1a) of the light transmitting substrate, and a resist layer(3) formed on the light shielding layer. A region on which the light shielding layer is formed is larger than a region on which the resist layer is formed. A circumferential part(2b) of the light shielding layer is exposed to the outside in comparison with a circumferential part of the resist layer. In the resist layer, a coating region of the circumferential part of the light shielding layer is exposed.

Description

Photomask Blank, Photomask Blank Manufacturing Method, Photomask, Photomask Manufacturing Method, Photomask Intermediate and Pattern Transfer Method

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a photomask used for transferring a pattern in a lithography technique, a photomask blank which is an original material thereof, a manufacturing method thereof, and a method for transferring a photomask intermediate and a pattern.

Conventionally, in lithography, pattern transfer is performed using a photomask. The photomask is manufactured using the photomask blank as a raw material raw material.

The photomask blank is formed by forming a light shielding film containing, for example, chromium as a main component, on a main surface of a translucent substrate made of quartz glass or the like. In the manufacture of such a photomask blank, first, quartz glass or the like is precisely polished to obtain a light transmissive substrate (polishing step). Next, the light shielding film which has chromium as a main component is formed in the main surface of the obtained translucent board | substrate by sputtering etc. (film-forming process).

The photomask is formed by applying a resist film on the light shielding film of the photomask blank (coating step), selectively exposing the resist film (exposure step), developing the exposed resist film, performing an etching process, and patterning the light shielding film. It is manufactured by the (etching treatment process).

By the way, in any of a photomask and a photomask blank, the outer peripheral part and side surface part of a translucent board | substrate are gripped when conveying this between each process. At this time, the light shielding film formed in the outer peripheral part or the side part of the translucent board | substrate used as a gripping clearance part [= marginal part to be held by hand or tools] may peel by gripping. When the light shielding film is peeled off, the peeling material adheres to the light shielding film pattern as particles, which causes defects such as light shielding film residues. In order to remove such peelings, the number of cleaning of the photomask blank or the photomask must be increased.

Therefore, it is proposed not to form a light shielding film in the outer peripheral part of a photomask blank, and to reduce generation | occurrence | production of the peeling material (particle) of a light shielding film at the time of holding a photomask blank. That is, in the International Publication No. 2004/051369 pamphlet (hereinafter referred to as "Patent Document 1"), a light shielding film is formed only at a portion except the peripheral portion of the light transmissive substrate, and the laser having the peripheral portion of the light transmissive substrate as the unfilmed region of the light shielding film. Photomask blanks for drawing are described. In this photomask blank, one side of the size of a light transmissive substrate is 300 mm or more, and the width | variety of the unfilmed area | region of a light shielding film is 3 mm or more. In this photomask blank, it is said that generation | occurrence | production of the particle from the side surface of a translucent board | substrate is prevented at the time of handling, especially when holding an outer peripheral part or a side part.

In the photomask blank of patent document 1 mentioned above, peeling of the light shielding film from the outer peripheral part or side surface part of a translucent board | substrate is prevented, and it seems that there exists a fixed effect in the prevention of particle generation.

However, in the film-forming process of the light shielding film of this photomask blank, when forming by a sputtering method, masking is performed using a sputtering mask in order to form an unfilmed area | region. At this time, in the vicinity of the boundary between the non-filmed region and the non-filmed region, the sputter material returned from the gap of the sputtering mask is adhered to the translucent substrate, and the film having a film thickness smaller than the set film thickness of the light shielding film and having a nonuniform film thickness Is formed. In most cases, such a film is formed in a state in which the film thickness gradually decreases toward the peripheral side of the light-transmissive substrate.

Such a film is likely to be peeled off due to the nonuniformity of the film thickness. Specifically, such a film is peeled off in the conveyance of a photomask blank, adhesion to an aligner (exposure), and many other scenes, and it cannot be avoided to adhere to a photomask as a particle.

For this reason, in this photomask blank, the trouble at the time of exposure, such as a light shielding film remainder, cannot be avoided. In addition, in order to remove such particles, for example, the number of cleanings before the formation of the particles must be increased.

Therefore, this invention is proposed in view of the above-mentioned situation, The objective is to prevent peeling of the light-shielding film peripheral part in handling, such as conveyance and installation to an aligner, and to prevent particle | grains resulting from peeling of a light-shielding film. It is to provide a photomask blank capable of inhibiting occurrence and a method for producing such a photomask blank.

In addition, another object of the present invention, by using such a photomask blank, the peeling of the light-shielding film peripheral portion is prevented in the handling of conveyance of the photomask blank, installation on the aligner, etc., particles resulting from the peeling of the light-shielding film The present invention provides a photomask intermediate and a photomask in which the occurrence of is suppressed and the productivity is improved, and a method for producing such a photomask.

Still another object of the present invention is to improve the yield of the exposure step in the manufacture of the photomask, thereby making it possible to reduce the number of cleanings (washing before forming a pellicle) during the photomask manufacturing step, thereby improving productivity. It is to let.

Another object of the present invention is to provide a method of transferring a pattern using such a photomask.

In order to solve the problem mentioned above and achieve the said objective, the photomask blank which concerns on this invention has either of the following structures.

[Configuration 1]

In a photomask blank in which a light shielding film is formed on a main surface of a light-transmissive substrate, and a resist film is formed on the light shielding film, a region in which a light shielding film is formed is larger than a region in which a resist film is formed, and the peripheral portion of the light shielding film is exposed to the outside of the peripheral edge of the resist film. It is characterized by being.

In the photomask blank according to the present invention having the configuration 1, the area in which the light shielding film is formed is larger than the area in which the resist film is formed, and the peripheral part of the light shielding film is exposed to the outer side of the peripheral part of the resist film. Removed. By removing the peripheral part of a light shielding film, peeling of the light shielding film peripheral part is prevented and generation | occurrence | production of the particle resulting from peeling of a light shielding film is suppressed.

In addition, in the present invention, in the expressions such as "a light shielding film is formed on the main surface of the light-transmissive substrate" and "a resist film is formed on the light shielding film 3", etc., "on" may be directly and via another film. It may be indirect. The same applies to each of the following configurations.

[Configuration 2]

A photomask blank in which a light shielding film is formed on a main surface of a light-transmissive substrate, and the resist film is formed by covering the light shielding film on the light shielding film, wherein the resist film is characterized by exposing an area covering the peripheral portion of the light shielding film. .

In the photomask blank according to the present invention having the configuration 2, the area of the resist film (positive resist) that covers the peripheral portion of the light shielding film is exposed, so that in a later step, the area covering the peripheral part of the light shielding film of the resist film is It is developed and removed, and in the later step, the peripheral portion of the light shielding film is removed. By removing the peripheral part of the light shielding film, peeling of the peripheral part of the light shielding film is prevented, and generation | occurrence | production of the particle resulting from peeling of the light shielding film is suppressed.

The manufacturing method of the photomask blank which concerns on this invention has either of the following structures.

[Configuration 3]

In the manufacturing method of the photomask blank which has a film-forming process which forms a light shielding film on the main surface of a translucent board | substrate, and the application | coating process which apply | coats a resist film on a light shielding film, in a film-forming process, the outer peripheral part along the periphery of the main surface of a light transmissive board | substrate To the non-forming region of the light shielding film, in the application step, by applying a resist film to a region including the region where the light shielding film is formed, the peripheral edge of the light shielding film is covered with the resist film, and after the application step, the peripheral part of the applied resist film is removed And a resist peripheral removal step of exposing the peripheral portion of the light shielding film.

In the manufacturing method of the photomask blank which concerns on this invention which has a structure 3, after the application | coating process of apply | coating a resist film, the periphery part of a light shielding film is exposed by removing the periphery part of the applied resist film, In the post process, the peripheral edge of a light shielding film The part is removed. By removing the peripheral part of a light shielding film, peeling of the light shielding film peripheral part is prevented and generation | occurrence | production of the particle resulting from peeling of a light shielding film is suppressed.

[Configuration 4]

In the method for manufacturing a photomask blank having the configuration 3, the resist peripheral removal step is performed by exposing from the backside side of the light transmissive substrate using a light shielding film as a photomask to reduce the peripheral part of the resist film to remove the phenomenon due to development in a later step. And a post-process for removing the peripheral portion of the resist film by development.

In the method for manufacturing a photomask blank according to the present invention having the constitution 4, the peripheral portion of the resist film is exposed by using the light shielding film as a mask by exposing from the backside side of the light transmissive substrate to enable removal by development in a later step, and the resist Since the peripheral part of the film is removed by development, in the later step, the peripheral part of the light shielding film is removed. By removing the peripheral part of a light shielding film, peeling of the light shielding film peripheral part is prevented and generation | occurrence | production of the particle resulting from peeling of a light shielding film is suppressed.

[Configuration 5]

In the manufacturing method of the photomask blank which has a film-forming process of forming a light shielding film on the main surface of a light-transmissive substrate, and the application | coating process of apply | coating a resist film on a light shielding film, in a coating process, a resist film is provided in the area | region containing the area | region in which the light shielding film was formed. It has a resist peripheral removal process which coat | covers the peripheral edge of a light shielding film by apply | coating and coat | covers the peripheral edge of a light shielding film by a resist film, and removes the peripheral part of the applied resist film after an application | coating process.

In the manufacturing method of the photomask blank which concerns on this invention with a structure 5, after the application | coating process of apply | coating a resist film, the periphery part of a light-shielding film is exposed by removing the periphery part of the apply | coated resist film. The part is removed. By removing the peripheral part of a light shielding film, peeling of the light shielding film peripheral part is prevented and generation | occurrence | production of the particle resulting from peeling of a light shielding film is suppressed.

[Configuration 6]

In the method of manufacturing the photomask blank having the configuration 3 or 5, the resist peripheral removal step is performed by selectively exposing the resist film to a region where the resist film is removed to expose the resist film to enable removal by development in a later step. And a post-process for removing the peripheral portion of the resist film by development.

In the method for manufacturing a photomask blank according to the present invention having the configuration 6, the resist film is selectively exposed to a region for removing the resist film to expose the resist film to enable removal by development in a later step, and the peripheral portion of the resist film is subjected to development. In this step, the peripheral portion of the light shielding film is removed. By removing the peripheral part of a light shielding film, peeling of the light shielding film peripheral part is prevented and generation | occurrence | production of the particle resulting from peeling of a light shielding film is suppressed.

[Configuration 7]

In the manufacturing method of the photomask blank of the structure 3 or the structure 5, the resist peripheral removal process removes the peripheral part of the resist film by making a solvent contact the peripheral part of a resist film.

In the manufacturing method of the photomask blank which concerns on 7 with this structure, since the peripheral part of the said resist film is removed by making a solvent contact the peripheral part of a resist film, the peripheral part of a light shielding film is removed in a later process. By removing the peripheral part of a light shielding film, peeling of the light shielding film peripheral part is prevented and generation | occurrence | production of the particle resulting from peeling of a light shielding film is suppressed.

[Configuration 8]

In the manufacturing method of the photomask blank which has a film-forming process which forms a light shielding film on the main surface of a translucent board | substrate, and a coating process which apply | coats a resist film on a light shielding film, in a coating process, the application | coating area | region of a resist is made smaller than the formation area of a light shielding film. And the peripheral portion of the light shielding film is exposed.

In the manufacturing method of the photomask blank which concerns on this invention which has a structure 8, in the application | coating process of apply | coating a resist film, since the application | coating area | region of a resist is made smaller than the formation area of a light shielding film, the peripheral part of a light shielding film is exposed, In the process, the peripheral portion of the light shielding film is removed. By removing the peripheral part of a light shielding film, peeling of the light shielding film peripheral part is prevented and generation | occurrence | production of the particle resulting from peeling of a light shielding film is suppressed.

As described above, in the present invention, since the peeling of the light-shielding film peripheral part does not occur in the handling of conveyance during use of the photomask, installation on the aligner, and the like, generation of particles due to the peeling-shielding film is suppressed.

That is, the present invention provides a photomask blank and such a photomask blank which can prevent peeling of the peripheral part of the light shielding film in the handling of conveyance, installation on the aligner, etc., and can suppress generation of particles due to peeling of the light shielding film. It is possible to provide a method for producing.

The photomask intermediate which concerns on this invention has the following structures.

[Configuration 9]

In a photomask intermediate in which a light shielding film is formed on a main surface of the light transmissive substrate, and a resist film is formed on the light shielding film, the light shielding film and the resist film have non-forming regions on the outer circumferential portion along the circumference of the main surface of the light transmissive substrate. The end face of the peripheral edge of the film is characterized by substantially coinciding with the direction perpendicular to the main surface of the light transmissive substrate.

In the photomask intermediate according to the present invention having the configuration 9, the outer peripheral portion along the periphery of the main surface of the light transmissive substrate has a non-forming region of the light shielding film and the resist film, and the end faces of the light permeation film and the resist film are peripheral surfaces of the light transmissive substrate. Since it substantially coincides with the vertical direction with respect to, the peeling of the light shielding film peripheral part is prevented, and generation | occurrence | production of the particle resulting from peeling of the light shielding film is suppressed.

The photomask which concerns on this invention has either of the following structures.

[Configuration 10]

A photomask having a light shielding film having a predetermined pattern formed on a main surface of a light transmissive substrate, the photomask having a non-forming area where no light shielding film is formed on an outer circumferential portion along the periphery of the main surface of the light transmissive substrate, = located adjacent to] The area where the film thickness of the light shielding film is less than the set film thickness of the light shielding film in the vicinity of the peripheral surface of the peripheral edge of the light shielding film is an area where the distance from the boundary between the light shielding film and the non-forming region is less than 500 µm. It is characterized by that.

In the photomask according to the present invention having the constitution 10, in the peripheral portion along the periphery of the main surface of the light transmissive substrate, there is a non-forming region in which no light shielding film is formed, and in the vicinity of the end surface of the peripheral edge of the light-shielding film facing the non-forming region, Since the distance from the boundary between the light shielding film and the non-forming area is less than 500 µm, the area where the film thickness of the light shielding film is less than the set film thickness of the light shielding film is prevented from peeling off the peripheral part of the light shielding film. Generation of particles due to peeling is inhibited.

[Configuration 11]

In the photomask having the constitution 10, the area where the film thickness of the light shielding film is less than the set film thickness of the light shielding film is an area where the film thickness is less than 98% of the set film thickness.

In the photomask according to the present invention having the structure 11, the area where the film thickness of the light shielding film is less than the set film thickness of the light shielding film is a region where the film thickness is less than 98% of the set film thickness, Peeling is prevented and generation | occurrence | production of the particle resulting from peeling of a light shielding film is suppressed.

[Configuration 12]

A photomask having a light shielding film having a predetermined pattern formed on a main surface of a light transmissive substrate, wherein the light shielding film has a non-formed area where no light shielding film is formed on an outer circumferential portion along the periphery of the main surface of the light transmissive substrate and faces a non-formed area. The end surface of the peripheral edge of is characterized in that it is an interface with the etching target region subjected to the etching treatment for this light shielding film.

In the photomask according to the present invention having the configuration 12, the light shielding film has a non-forming area in which the light shielding film is not formed on the outer circumferential portion along the circumference of the main surface of the light transmissive substrate, and the end face of the peripheral edge of the light shielding film that faces the non-forming area is formed in the light shielding film. Since it becomes an interface with the to-be-etched area | region which performed the etching process, peeling of the peripheral part of a light shielding film is prevented and generation | occurrence | production of the particle resulting from peeling of a light shielding film is suppressed.

The manufacturing method of the photomask which concerns on this invention has either of the following structures.

[Configuration 13]

A photomask manufacturing method in which a light shielding film is formed on a main surface of a light transmissive substrate, and a predetermined pattern is formed in the light shielding film by using a photomask blank in which a resist film is formed on the light shielding film, wherein a region of a predetermined width of the peripheral portion of the light shielding film is formed. It is characterized by having a step of removing.

In the manufacturing method of the photomask which concerns on this invention which has the structure 13, since the area | region of the predetermined width | variety of the peripheral part of a light shielding film is removed, peeling of the light shielding film peripheral part is prevented and generation | occurrence | production of the particle resulting from peeling of a light shielding film is suppressed. .

[Configuration 14]

A photomask blank in which a light shielding film is formed on the main surface of the light transmissive substrate, a resist film is formed on the light shielding film, and a region in which the light shielding film is formed is larger than the region in which the resist film is formed, and the peripheral portion of the light shielding film is exposed to the outside of the peripheral edge of the resist film. In the method of manufacturing a photomask in which a predetermined pattern is formed on a light shielding film, a process of forming a resist pattern by exposing and developing a predetermined pattern to a resist film, and selectively forming a light shielding film using the resist pattern as a mask It has a process of forming the predetermined pattern in this light shielding film, and removing the peripheral part of the light shielding film exposed to the outer side rather than the peripheral edge of a resist film by removing.

In the method of manufacturing the photomask according to the present invention having the configuration 14, since the peripheral portion of the light shielding film exposed to the outer side of the resist film is removed, the peeling of the light shielding film peripheral part is prevented, and generation of particles due to the peeling of the light shielding film is prevented. It is forced.

[Configuration 15]

A light shielding film is formed on the main surface of the light transmissive substrate, a resist film is formed on the light shielding film, and a predetermined pattern is formed on the light shielding film by using a photomask blank in which a region covering the peripheral portion of the light shielding film of the resist film is exposed. In the method of manufacturing a photomask, a step of forming a resist pattern by exposing and developing a predetermined pattern to a resist film and selectively removing the light shielding film using the resist pattern as a mask to form a predetermined pattern in the light shielding film. And a peripheral portion of the light shielding film exposed outside the peripheral edge of the resist film.

In the method for manufacturing a photomask according to the present invention having the configuration 15, since the peripheral portion of the light shielding film exposed to the outside of the peripheral edge of the resist film is removed, the peeling of the light shielding film peripheral part is prevented, and generation of particles due to the peeling of the light shielding film is prevented. It is forced.

[Configuration 16]

A photomask manufacturing method in which a light shielding film is formed on a main surface of a light transmissive substrate and a predetermined pattern is formed in the light shielding film by using a photomask blank in which a resist film is formed on the light shielding film, wherein the predetermined pattern is exposed to the resist film. In addition, the step of exposing the area corresponding to the peripheral portion of the light shielding film of the resist film, the step of developing the resist film to form a resist pattern, and selectively removing the light shielding film using the resist pattern as a mask, And forming a pattern of and removing the peripheral portion of the light shielding film exposed outside the peripheral edge of the resist film.

In the method of manufacturing the photomask according to the present invention having the configuration 16, since the peripheral portion of the light shielding film exposed to the outside of the peripheral edge of the resist film is removed, peeling of the light shielding film peripheral portion is prevented, and generation of particles due to the peeling of the light shielding film is prevented. It is forbidden.

[Configuration 17]

In the method for manufacturing a photomask having any one of Configurations 13 to 16, the peripheral portion of the light shielding film to be removed includes at least a part of a region where the film thickness is less than the set film thickness of the light shielding film. .

In the manufacturing method of the photomask which concerns on this invention which has the structure 17, since the peripheral part of the light shielding film removed contains at least one part of the area | region whose film thickness is less than the setting film thickness of a light shielding film, peeling of the light shielding film peripheral part is prevented As a result, generation of particles due to peeling of the light shielding film is suppressed.

That is, according to the present invention, by using the photomask blank as described above, in the handling of conveyance of the photomask blank, installation on the aligner, and the like, the peeling of the light shielding film peripheral part is prevented and the particles resulting from the peeling of the light shielding film are prevented. It can suppress generation | occurrence | production, and can provide the photomask intermediate and photomask which improved productivity, and the manufacturing method of such a photomask.

That is, in the manufacture of a photomask, the present invention can greatly improve the yield of an exposure step, thereby making it possible to reduce the number of cleanings (washing before forming a pellicle) during the photomask manufacturing process, thereby improving productivity. have.

The pattern transfer method of the present invention has the following configuration.

[Configuration 18]

Using the photomask manufactured by the photomask of the structure 10 or the structure 11, or the photomask which has any one of the structures 13-17, the pattern formed in the light shielding film of this photomask has a laser light source. It is characterized by transferring to a transfer subject by a drawing device.

In the method for transferring a pattern according to the present invention having the configuration 18, a pattern formed on the light shielding film of the photomask using the photomask according to the present invention or the photomask manufactured by the method for producing a photomask according to the present invention. Since the film is transferred to the transfer target by a drawing machine, peeling of the peripheral part of the light shielding film of the photomask is prevented, and generation of particles due to peeling of the light shielding film is suppressed, so that the pattern can be transferred satisfactorily.

EMBODIMENT OF THE INVENTION Hereinafter, the best embodiment for implementing this invention is demonstrated.

[Embodiment of Manufacturing Method of Photomask Blank]

Hereinafter, the manufacturing method of the photomask blank which concerns on this invention is demonstrated in order of each process. Moreover, the photomask blank which concerns on this invention is manufactured by implementing the manufacturing method of the photomask blank which concerns on this invention.

[1] film forming process

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows each process of the manufacturing method of the photomask blank which concerns on this invention.

First, as shown to (a) in FIG. 1, the main surface 1a of the translucent board | substrate 1 which consists of quartz glass etc. is precisely grind | polished, and on the main surface 1a of this translucent board | substrate 1, The light shielding film 2 is formed by means, such as sputtering.

As the transparent substrate 1, for example, a thickness of about 5 mm to 15 mm can be used. As the light shielding film 2, it is preferable to have chromium as a main component, but it is not limited to this. In addition, the light shielding film 2 may be a semi-transmissive film which transmits a part of the exposure light. The light shielding film 2 may be a film obtained by stacking a plurality of films (for example, a plurality of light shielding films, or a light shielding film and a semi-transmissive film).

2 is a cross-sectional view showing the configuration of a photomask blank in which a light shielding film is formed over the entire main surface of the transparent substrate.

In the formation of the light shielding film 2, as shown in FIG. 2, the light shielding film 2 may be formed on the entire main surface 1a of the light transmissive substrate 1 by sputtering or the like. However, when the light shielding film 2 is formed on the entire main surface 1a of the light transmissive substrate 1, the following adverse effects are caused. That is, the material of the light shielding film 2 returns to the end surface (side surface) 1b of the translucent board | substrate 1, and is formed into a film. When the film of this end surface part supports the translucent board | substrate 1 at the time of conveyance before and behind a post process, for example, the process of apply | coating a resist to the translucent board | substrate 1, it peels and becomes a particle. Therefore, in formation of the light shielding film 2, it is preferable to leave the part along the periphery of the main surface 1a of the translucent board | substrate 1 as the non-forming area | region of the light shielding film 2. When the peripheral part of the main surface 1a of the translucent substrate 1 is a film non-forming region, the worry of particle generation as described above is eliminated. In addition, it is preferable to make the non-formation area | region of the light shielding film 2 into the range of the width of about 1 mm-about 10 mm from the periphery of the main surface 1a of the translucent board | substrate 1.

When forming the light shielding film 2 by sputtering, in order to form the non-formation area | region 2a, you may perform sputtering by masking the part along the periphery of the main surface 1a of the translucent board | substrate 1. In this case, however, the sputter material returned from the gap between the light transmissive substrate 1 and the sputtering mask is attached to the light transmissive substrate 1. As a result, along the periphery of the light shielding film 2, a film 2b having a nonuniform film thickness is formed with a film thickness not reaching the set film thickness of the light shielding film 2. For example, assume that the set film thickness of the light shielding film 2 is a predetermined value between 80 nm (800 kPa) and 150 nm (1500 kPa). In such a situation, on the peripheral side of the light shielding film 2, on the peripheral side of the setting film 2, an uneven film thickness region 2b gradually decreases from this setting film thickness and reaches zero (non-formation) is formed. do. In most cases, the part 2b which does not reach the set film thickness was formed in the width | variety of 1 mm or more (for example, 1 mm-1.5 mm) in the periphery of the light shielding film. Here, the set film thickness means a film thickness set as the light shielding film. Therefore, although the set film thickness is the film thickness of parts other than the said peripheral part, it can conveniently be set as the film thickness of the film center vicinity. In addition, according to the measurement by the styling method, the setting film thickness part becomes 30 nm (300 micrometers) or less of film thickness fluctuations. On the other hand, there exists a part in which the film thickness fluctuation becomes 50 nm (500 micrometers) or more in the said peripheral part.

Such a region 2b in which the film thickness on the peripheral side of the light shielding film 2 is nonuniform may peel off and cause particles to be generated. In this invention, the area | region 2b in which such a film thickness is nonuniform is removed by the etching process etc. in the following process mentioned later. That is, in the present invention, it is possible to eliminate the above-described portions of 50 nm or more in film thickness variation.

[2] resist coating step

Next, as shown to (b) in FIG. 1, the resist material is apply | coated on the light shielding film 2 formed on the translucent board | substrate 1, and the resist film 3 is formed. It is preferable that the formation region (coating region of the resist material) of the resist film 3 includes the entire formation region of the light shielding film 2. That is, the resist film 3 is formed covering the entire light shielding film 2 and is also formed on the non-forming region 2a of the light shielding film 2. However, it is preferable to form the resist film 3 only on the main surface 1a of the light transmissive substrate 1. This is because when the resist film returns to the end face 1b of the light transmissive substrate 1 or the chamfer formed on the end face 1b, the resist film of the part may peel off and generate particles.

As a coating method of a resist material, the method using a well-known apparatus, such as a spin coater, can be used. Moreover, you may apply | coat a resist material by what is called a cap coater. In the method using this cap coater, first, the resist material is raised by capillary action in the nozzle with the opening end facing upward. Next, the resist material which reached the opening edge of this nozzle is made to contact the to-be-coated surface of the translucent board | substrate 1 facing downward. Then, the resist film 3 is formed in the to-be-coated surface of the translucent board | substrate 1 by moving these nozzles and the translucent board | substrate 1 relative.

In this step, it is possible to make the formation region of the resist film 3 smaller than the formation region of the light shielding film 2. Even when the non-forming region 2a of the light shielding film 2 is formed at the peripheral portion of the main surface 1a of the light transmissive substrate 1, as shown in FIG. 2, the light shielding film 2 is formed of a light transmissive substrate ( Even when the film is formed over the entire main surface 1a of 1), the formation region of the resist film 3 can be made smaller than the formation region of the light shielding film 2. In this case, it becomes possible to omit the partial removal process of the [3] resist mentioned later.

However, from the viewpoints of stability of the film quality of the resist film 3, simplicity of the coating apparatus of the resist material, and the like, the formation region of the resist film 3 includes the formation region of the light shielding film 2, and the resist film ( It is preferable that 3) covers the light shielding film 2.

[3] partial removal of resist

In the above-mentioned process, when the resist film 3 is formed so that the light shielding film 2 may be covered, in this process, as shown to (c) in FIG. 1, the peripheral part of this resist film 3 is carried out. (3a) is removed to obtain a resist film 3A from which the peripheral portion is removed. That is, by removing the peripheral part 3a of the resist film 3, the peripheral part 2b of the light shielding film 2 formed in the lower layer of the resist film 3A from which this peripheral part was removed is exposed outside.

The region 3a from which the resist film 3 has been removed becomes a region from which the light shielding film 2 is removed by etching or the like in a subsequent step described later. Therefore, according to the area | region which needs to remove the light shielding film 2, the area | region 3a which removes the resist film 3 is determined.

As a method of removing the predetermined region 3a of the resist film 3, the following method can be used. That is, in the removal method, the solvent of a resist material is made to contact the predetermined area | region 3a of the resist film 3, and this solvent is removed with the resist film 3 of a predetermined area | region. For example, the following removal method is considered. First, the main surface of the resist film 3 other than the region 3a from which the resist film 3 is removed is covered with a cover member. Then, the solvent of a resist material is supplied from this cover member. And the removal part of the resist film 3 is melt | dissolved through the supply hole formed in the cover member. In addition, as another removal method, the solvent may be supplied to the removal portion 3a of the resist film 3 by the nozzle, and the control may be performed such that the solvent reaches only the removal portion 3b. Or as another removal method, you may make it remove the removal part 3a of the resist film 3 with the cloth containing the solvent of the resist material.

3 is a cross-sectional view showing a state of exposing the peripheral portion of the resist film.

In this step, the predetermined region 3a of the resist film 3 is not removed. As shown in FIG. 3, the region is formed using the light shielding mask 4 and the light source 5. Only selective exposure to (3a) may be performed. In other words, the light beam from the light source 5 does not reach the central portion of the resist film 3 by being blocked by the light shielding mask 4. On the other hand, the light flux from the light source 5 reaches the outer peripheral part 3a of the resist film 3 through the outer peripheral side of the light shielding mask 4, and reaches the resist film 3 of this part 3a. Photosensitive. In this case, the region 3a on which the resist film 3 is exposed is developed and removed in a subsequent step to be described later or a step of manufacturing a photomask to be described later.

In addition, as shown in FIG. 4, the light shielding film 2 is shielded by injecting the light beam from the light source 5 from the back surface 1c side of the light transmissive substrate 1 without using the light shielding mask 4. As a result, only the peripheral portion 3a of the resist film 3 can be selectively exposed. In other words, the light beam from the light source 5 does not reach the center portion of the resist film 3 by being blocked by the light shielding film 2. On the other hand, the light beam from the light source 5 reaches the outer peripheral part 3a of the resist film 3 through the outer peripheral side of the light shielding film 2, and the resist film 3 of this part 3a is photosensitive. Let's do it. Also in this case, the region 3a on which the resist film 3 is exposed is developed and removed in a subsequent step to be described later or a step of manufacturing a photomask to be described later.

In this case, in the peripheral part of the light shielding film 2 formed on the light transmissive substrate 1, since the light shielding is insufficient for the part 2b of the film thickness which lacks the design film thickness, a part of the light beam from a light source is transmitted. The resist film 3 is then exposed. Therefore, the amount of light emitted from the light source 5 should be such that the resist film 3 at the peripheral part of the light shielding film 2 is sufficiently exposed. On the other hand, in the area | region where the light shielding film 2 has sufficient film thickness, since the light beam from the light source 5 does not permeate | transmit, the resist film 3 is not exposed.

In this step, in the photomask blank in which the peripheral portion 3a of the resist film 3 is exposed, the peripheral portion 3a of the resist film 3 is developed and then removed. As described later, the resist film 3 in the photomask blank may be developed so that the peripheral portion 3a is simultaneously developed and removed in the pattern development step in the photomask manufacturing step.

In addition, the selective exposure to the removal part 3a of the peripheral side of the resist film 3 may be performed in the manufacturing process of the photomask mentioned later, without performing in the manufacturing process of a photomask blank. Specifically, the selective exposure to the resist film 3 may be performed simultaneously with the pattern writing on the resist film 3, before the pattern writing, or after the pattern writing. However, selective exposure to the resist film 3 is preferably performed in this step as described above.

Through each of the above-described steps, a photomask blank according to the present invention is produced.

[Embodiment of Manufacturing Method of Photomask]

Hereinafter, the manufacturing method of the photomask which concerns on this invention is demonstrated in order of each process. Further, by carrying out the photomask manufacturing method according to the present invention, the photomask according to the present invention is produced.

The manufacturing method of this photomask is performed using the photomask blank which concerns on this invention mentioned above. However, when selectively exposing the removal part 3a on the peripheral side of the resist film 3 in the manufacturing process of this photomask, it uses a conventional photomask blank. In the conventional photomask blank, a resist film 3 is formed on the light shielding film 2 formed on the transparent substrate 1 by covering the light shielding film 2. The resist film 3 is formed on the light shielding film 2. It means that no exposure is performed.

[1] pattern drawing process

Using the above-described photomask blank, the resist film 3A is baked as needed, and then pattern drawing (selective exposure) is performed on the resist film 3A based on the desired pattern. This pattern drawing can be performed using a laser drawing machine, for example.

In addition, when using the drawing machine which uses an electron beam, it is preferable that the peripheral part of the translucent board | substrate 1 is electroconductive for preventing the charge-up of the translucent board | substrate 1. On the other hand, when using a laser drawing machine, the peripheral part of the translucent board | substrate 1 does not need to be electroconductive. Therefore, in this invention, when forming the non-formation area | region 2a of the light shielding film 2 in the peripheral part of the translucent board | substrate 1, it is preferable to use a laser drawing machine.

In addition, in the manufacturing process of the photomask blank mentioned above, it is assumed that the selective exposure with respect to the removal part on the peripheral side of the resist film 3 is not performed. In this case, in this step, selective exposure to the peripheral side of the resist film 3 is performed simultaneously with the pattern writing to the resist film 3, or before the pattern writing or after the pattern writing. . The selective exposure to the peripheral side of the resist film 3 performed here is the same as that described in the manufacturing process of a photomask blank.

[2] development and etching processes

The resist film 3A on which the pattern drawing is completed is developed to form a resist pattern. In addition, in the manufacturing process of the photomask blank mentioned above, when only the exposure is performed with respect to the peripheral part 3a of the resist film 3, when the removal is not performed, an exposure part is removed in this developing process. .

The light shielding film pattern is formed by etching the light shielding film 2 using the resist pattern thus formed as a mask. Although there is no restriction | limiting in particular in the method of an etching process, For example, a well-known wet etching process can be used. At this time, since the peripheral part 2b of the light shielding film 2 is not covered by the resist film 3A, this peripheral part 2b is also removed by an etching process. At this time, the width | variety from the periphery of the translucent board | substrate 1 becomes 1 mm-20 mm in the non-formation area | region 2a of the light shielding film 2, for example.

By this process, the film 2b in which the film thickness formed on the peripheral side of the light shielding film 2 is nonuniform and lacks the set film thickness of the light shielding film 2 is removed. As described above, the film 2b in which the film thickness is nonuniform and the set film thickness of the light shielding film 2 is insufficient is formed at the time of sputter film formation of the light shielding film 2. The peripheral part 2b of the light shielding film 2 removed at this process is a part less than 98% of the setting film thickness of the light shielding film 2, for example. As described above, the set film thickness of the light shielding film 2 is a predetermined film thickness within a range of, for example, 80 nm (800 kPa) to 150 nm (1500 kPa).

5 is a cross-sectional view showing the configuration of a photomask intermediate according to the present invention.

Thus, by removing the peripheral part 2b of the light shielding film 2, as shown in FIG. 5, the light shielding film 2A and resist are formed in the outer peripheral part along the peripheral edge of the main surface 1a of the translucent board | substrate 1, as shown in FIG. A so-called photomask intermediate having non-forming regions 2a and 3a of the film 3A is constructed. In this photomask intermediate, the peripheral surfaces 2Aa and 3Aa of the light shielding film 2A and the resist film 3A substantially coincide in the direction perpendicular to the main surface 1a of the light transmissive substrate 1.

[3] resist removal process

Next, the unnecessary resist film 3A is removed by a known method. Thereby, the photomask in which the patterned light shielding film 2A was precisely formed on the translucent board | substrate 1 is completed. This photomask has the non-formation area | region 2a of the light shielding film 2A in the part along the periphery of the main surface 1a of the translucent board | substrate 1. In addition, the peripheral surface of the light shielding film 2A, that is, the end surface 2Aa of the peripheral edge of the light shielding film 2 which faces the non-forming region 2a, is an etching target region where etching treatment is performed on the peripheral part of the light shielding film 2A. It is an interface with and is the shape which rose substantially perpendicularly from the main surface 1a of the translucent board | substrate 1 in the direction perpendicular | vertical to this main surface 1a.

6 is a cross-sectional view showing the configuration of main parts of the photomask according to the present invention.

That is, in this photomask, as shown in Fig. 6, the light shielding film 2A is set in the vicinity of the end surface 2Aa of the peripheral surface facing the non-shaped region 2a, and the thickness of the light shielding film 2 is set. The area | region which is less than 98% of a film thickness becomes an area | region whose distance (width) from the boundary between this light shielding film 2A and the non-formation area | region 2a is less than 500 micrometers. Moreover, it is preferable that the area | region whose film thickness is less than 98% of the setting film thickness of 2 A of light shielding films is an area | region whose width is 100 micrometers or less, and it is more preferable if it is an area | region of 50 micrometers or less width.

[Embodiment of Pattern Transfer Method]

In this pattern transfer method, the pattern is exposed to the transfer object using the photomask manufactured as described above. The object to be transferred is, for example, a glass substrate for a liquid crystal display or a plasma display panel, a color filter, or the like, and there is no restriction on the use thereof.

In addition, the photomask according to the present invention is not limited in size. However, for example, when one side is the size of 300 mm or more, especially in the photomask which enlarged like the case where one side is 500 mm or more, the effect of this invention becomes especially remarkable.

That is, the photomask used for manufacture of display apparatuses, such as a liquid crystal display and a plasma display panel, tends to enlarge with the large area of a display screen. As the photomask becomes larger, the thicker and heavier the photomask is, the higher the risk of particle generation due to peeling of the light shielding film. The reason for this is as follows. When handling this, the photomask needs to be reliably maintained by using the jig which fits the outer peripheral part. However, the heavier the photomask is, the greater the load is placed on the contact portion with the jig, that is, the outer circumferential portion, and the light shielding film 2 at this portion is likely to peel off. Therefore, this invention exhibits a remarkable effect especially in the enlarged photomask.

<Example>

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described.

First, as shown in Fig. 1 (a), chromium is the main component on the main surface 1a of the translucent substrate 1 made of quartz glass polished of the main surface 1a by sputtering. The light shielding film 2 of 100 nm (1000 micrometers) film thickness was formed into a film. At this time, the part of width 3mm from the periphery of the main plane 1a of the translucent board | substrate 1 shielded chromium by arrange | positioning the masking jig at the time of sputter film deposition, and set it as the non-formation area | region 2a.

Next, as shown in Fig. 1 (b), by using a cap coater, a resist film 3 having a film thickness of 1.0 mu m is applied to the entire surface of the main surface 1a of the light transmissive substrate 1, Baking after drying.

As shown in FIG. 1C, the peripheral portion 3a of the resist film 3 was removed from the peripheral edge of the light transmissive substrate 1 in a width of 6 mm. As a removal method, as shown in FIG. 4, the method of exposing from the back surface 1c side of the translucent board | substrate 1, and removing the resist film 3 by image development was employ | adopted.

In this way, a photomask blank was produced.

Next, about this photomask blank, the pattern for device substrate manufacture of a liquid crystal display panel was drawn using the drawing machine. After drawing, the image development and the etching process were performed by the well-known process, and the pattern was formed in 2 A of light shielding films. Then, as shown in Fig. 5, the unnecessary resist film 3A was removed.

In this way, a photomask was produced.

When the obtained photomask was visually checked and inspected, the periphery of the light shielding film 2A, that is, the boundary 2Aa between the light shielding film 2A and the non-forming region 2a had a clear boundary line. In addition, when the shape of the circumference of the light shielding film 2A was measured by a microscope and a contact film thickness meter, in the vicinity of the circumference of the light shielding film 2A, the film thickness was less than 98% of 100 nm (1000 kPa), which is the set film thickness. The width of was 50 µm or less. In other words, the end surface 2Aa of the peripheral edge of the light shielding film 2A was formed to rise almost vertically from the main surface 1a of the light transmissive substrate 1.

And washing was performed. In the washing step, when the number of foreign matters of 3 µm or more became 0 (zero) in the inspection after washing, the cleaning was carried out using the criterion of completing washing, but this criterion was cleared by one washing. Thereafter, the ferrule was formed.

On the other hand, as a comparative example, the photomask was produced by making the peripheral part 2b of the light shielding film 2 into the state after sputter film-forming was formed. As for this photomask, the part 2b of the film thickness lacking about 1 mm was observed visually at the periphery of the light shielding film 2. As shown in FIG. This photomask was used to form ferricles. In the foreign material confirmation before pericle formation, it confirmed that it was due to the influence of the periphery vicinity of the light shielding film 2, and in order to complete the pericle formation process, 8 washing | cleaning was required.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows each process of the manufacturing method of the photomask blank which concerns on this invention.

FIG. 2 is a cross-sectional view showing a configuration of a photomask blank in which a light shielding film is formed over the entire main surface of the light transmissive substrate. FIG.

3 is a cross-sectional view showing a state of exposing the peripheral portion of the resist film.

4 is a cross-sectional view showing a state of exposing the peripheral portion of a resist film using a light shielding film.

5 is a cross-sectional view showing a configuration of a photomask intermediate according to the present invention.

6 is a cross-sectional view showing a configuration of main parts of a photomask according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: translucent substrate

1a: main surface

1b: end face (side)

2: shading film

3: resist film

Claims (18)

As a photomask blank in which a light shielding film is formed on a main surface of a light transmissive substrate, and a resist film is formed on the light shielding film, The area | region in which the said light shielding film was formed is larger than the area | region in which the said resist film was formed, The peripheral part of the said light shielding film is exposed to the outer side rather than the periphery of the said resist film. A photomask blank in which a light shielding film is formed on a main surface of a light-transmissive substrate, and the light shielding film is coated on the light shielding film to form a resist film. The photoresist blank of the said resist film is exposed the area | region which coats the peripheral part of the said light shielding film. A method for producing a photomask blank, which has a film forming step of forming a light shielding film on a main surface of a light transmissive substrate and a coating step of applying a resist film on the light shielding film, In the film forming step, the outer peripheral portion along the circumference of the main surface of the light transmissive substrate is used as the non-forming region of the light shielding film, In the coating step, by applying a resist film to a region including a region where the light shielding film is formed, the peripheral edge of the light shielding film is covered with a resist film, After the coating step, the resist peripheral removal step of exposing the peripheral part of the light-shielding film by removing the peripheral part of the applied resist film Method for producing a photomask blank comprising a. The method of claim 3, The resist peripheral removal process, Exposing the light shielding film as a photomask to expose the periphery of the resist film by exposing from the backside side of the light transmissive substrate, thereby enabling removal by development in a later step; Post-process to remove the peripheral part of the resist film by development Method for producing a photomask blank comprising a. A method for producing a photomask blank, which has a film forming step of forming a light shielding film on a main surface of a light transmissive substrate and a coating step of applying a resist film on the light shielding film, In the coating step, by applying a resist film to a region including a region where the light shielding film is formed, the peripheral edge of the light shielding film is covered with a resist film, After the coating step, the resist peripheral removal step of exposing the peripheral part of the light-shielding film by removing the peripheral part of the applied resist film Method for producing a photomask blank comprising a. The method according to claim 3 or 5, The resist peripheral removal process, Selectively exposing the resist film to a region where the resist film is to be removed to expose the resist film, thereby enabling removal by development in a later step; Post-process to remove the peripheral part of the resist film by development Method for producing a photomask blank, characterized in that consisting of. The method according to claim 3 or 5, In the resist peripheral removal step, the peripheral portion of the resist film is removed by contacting the solvent with the peripheral portion of the resist film. A method for producing a photomask blank, which has a film forming step of forming a light shielding film on a main surface of a light transmissive substrate and a coating step of applying a resist film on the light shielding film, The said application process WHEREIN: The application area | region of the said resist film is made smaller than the formation area of the said light shielding film, and the peripheral part of the said light shielding film is exposed, The manufacturing method of the photomask blank characterized by the above-mentioned. As a photomask intermediate in which a light shielding film is formed on the main surface of the light-transmissive substrate, and a resist film is formed on the light shielding film, Having a non-forming region of the light shielding film and the resist film on an outer circumferential portion along a circumference of the main surface of the light transmissive substrate, A peripheral end surface of the light shielding film and the resist film substantially coincides with a direction perpendicular to the main surface of the light transmissive substrate. A photomask comprising a light shielding film having a predetermined pattern formed on a main surface of a light transmissive substrate, It has a non-formation area | region in which the said light shielding film is not formed in the outer peripheral part along the periphery of the main surface of the said translucent board | substrate, Near the end surface of the peripheral edge of the light shielding film that faces the non-forming area, the area where the film thickness of the light shielding film is less than the set film thickness of the light shielding film has a distance of 500 µm from the boundary between the light shielding film and the non-forming area. A photomask comprising less than one area. The method of claim 10, A region in which the film thickness of the light shielding film is less than the set film thickness of the light shielding film is a region in which the film thickness is less than 98% of the set film thickness. A photomask comprising a light shielding film having a predetermined pattern formed on a main surface of a light transmissive substrate, It has a non-formation area | region in which the said light shielding film is not formed in the outer peripheral part along the periphery of the main surface of the said translucent board | substrate, The end surface of the peripheral edge of the said light shielding film which faces said non-formation area | region is an interface with the to-be-etched area | region where the etching process with respect to the said light shielding film was performed. A method of manufacturing a photomask in which a light shielding film is formed on a main surface of a light transmissive substrate, and a predetermined pattern is formed in the light shielding film by using a photomask blank in which a resist film is formed on the light shielding film. And removing a region of a predetermined width of the peripheral portion of the light shielding film. A light shielding film is formed on the main surface of the light-transmissive substrate, a resist film is formed on the light shielding film, and a region where the light shielding film is formed is larger than a region where the resist film is formed, and the peripheral portion of the light shielding film is exposed to the outer side of the resist film. As a manufacturing method of a photomask which forms a predetermined pattern in the said light shielding film using a photomask blank, Exposing and developing the predetermined pattern to the resist film to form a resist pattern; Selectively removing the light shielding film by using the resist pattern as a mask to form the predetermined pattern on the light shielding film and to remove the peripheral portion of the light shielding film exposed to the outer side of the resist film Method of manufacturing a photomask comprising a. A light shielding film is formed on the main surface of the light transmissive substrate, a resist film is formed on the light shielding film, and a predetermined pattern is formed on the light shielding film by using a photomask blank in which an area covering the peripheral portion of the light shielding film of the resist film is exposed. As a method of manufacturing a photomask to form a Exposing and developing the predetermined pattern to the resist film to form a resist pattern; Selectively removing the light shielding film by using the resist pattern as a mask to form the predetermined pattern on the light shielding film and to remove the peripheral portion of the light shielding film exposed to the outer side of the resist film Method of manufacturing a photomask comprising a. A method of manufacturing a photomask in which a light shielding film is formed on a main surface of a light transmissive substrate, and a predetermined pattern is formed in the light shielding film by using a photomask blank in which a resist film is formed on the light shielding film. Exposing the predetermined pattern to the resist film and exposing the region corresponding to the peripheral portion of the light shielding film of the resist film; Developing the resist film to form a resist pattern; Selectively removing the light shielding film by using the resist pattern as a mask to form the predetermined pattern on the light shielding film and to remove the peripheral portion of the light shielding film exposed to the outer side of the resist film Method of manufacturing a photomask comprising a. The method according to any one of claims 13 to 16, The peripheral portion of the light shielding film to be removed includes at least a part of a region where the film thickness is less than the set film thickness of the light shielding film. Using the photomask manufactured by the photomask of Claim 10 or 11, or the photomask manufacturing method in any one of Claims 13-17, the pattern formed in the light shielding film of the photomask is a laser light source. The transfer method of the pattern characterized by the transfer to a transfer target object by the drawing machine which has the following.

Images